fix: billing (#5483)

apps/web/lib/organization/service.ts

@@ -3,6 +3,7 @@ import { cache } from "@/lib/cache";
 import { BILLING_LIMITS, ITEMS_PER_PAGE, PROJECT_FEATURE_KEYS } from "@/lib/constants";
 import { getProjects } from "@/lib/project/service";
 import { updateUser } from "@/lib/user/service";
+import { getBillingPeriodStartDate } from "@/lib/utils/billing";
 import { Prisma } from "@prisma/client";
 import { cache as reactCache } from "react";
 import { prisma } from "@formbricks/database";
@@ -337,19 +338,8 @@ export const getMonthlyOrganizationResponseCount = reactCache(
             throw new ResourceNotFoundError("Organization", organizationId);
           }
 
-          // Determine the start date based on the plan type
-          let startDate: Date;
-          if (organization.billing.plan === "free") {
-            // For free plans, use the first day of the current calendar month
-            const now = new Date();
-            startDate = new Date(now.getFullYear(), now.getMonth(), 1);
-          } else {
-            // For other plans, use the periodStart from billing
-            if (!organization.billing.periodStart) {
-              throw new Error("Organization billing period start is not set");
-            }
-            startDate = organization.billing.periodStart;
-          }
+          // Use the utility function to calculate the start date
+          const startDate = getBillingPeriodStartDate(organization.billing);
 
           // Get all environment IDs for the organization
           const projects = await getProjects(organizationId);

apps/web/lib/utils/billing.test.ts

@@ -0,0 +1,176 @@
+import { afterEach, beforeEach, describe, expect, test, vi } from "vitest";
+import { getBillingPeriodStartDate } from "./billing";
+
+describe("getBillingPeriodStartDate", () => {
+  let originalDate: DateConstructor;
+
+  beforeEach(() => {
+    // Store the original Date constructor
+    originalDate = global.Date;
+  });
+
+  afterEach(() => {
+    // Restore the original Date constructor
+    global.Date = originalDate;
+    vi.useRealTimers();
+  });
+
+  test("returns first day of month for free plans", () => {
+    // Mock the current date to be 2023-03-15
+    vi.setSystemTime(new Date(2023, 2, 15));
+
+    const organization = {
+      billing: {
+        plan: "free",
+        periodStart: new Date("2023-01-15"),
+        period: "monthly",
+      },
+    };
+
+    const result = getBillingPeriodStartDate(organization.billing);
+
+    // For free plans, should return first day of current month
+    expect(result).toEqual(new Date(2023, 2, 1));
+  });
+
+  test("returns correct date for monthly plans", () => {
+    // Mock the current date to be 2023-03-15
+    vi.setSystemTime(new Date(2023, 2, 15));
+
+    const organization = {
+      billing: {
+        plan: "scale",
+        periodStart: new Date("2023-02-10"),
+        period: "monthly",
+      },
+    };
+
+    const result = getBillingPeriodStartDate(organization.billing);
+
+    // For monthly plans, should return periodStart directly
+    expect(result).toEqual(new Date("2023-02-10"));
+  });
+
+  test("returns current month's subscription day for yearly plans when today is after subscription day", () => {
+    // Mock the current date to be March 20, 2023
+    vi.setSystemTime(new Date(2023, 2, 20));
+
+    const organization = {
+      billing: {
+        plan: "scale",
+        periodStart: new Date("2022-05-15"), // Original subscription on 15th
+        period: "yearly",
+      },
+    };
+
+    const result = getBillingPeriodStartDate(organization.billing);
+
+    // Should return March 15, 2023 (same day in current month)
+    expect(result).toEqual(new Date(2023, 2, 15));
+  });
+
+  test("returns previous month's subscription day for yearly plans when today is before subscription day", () => {
+    // Mock the current date to be March 10, 2023
+    vi.setSystemTime(new Date(2023, 2, 10));
+
+    const organization = {
+      billing: {
+        plan: "scale",
+        periodStart: new Date("2022-05-15"), // Original subscription on 15th
+        period: "yearly",
+      },
+    };
+
+    const result = getBillingPeriodStartDate(organization.billing);
+
+    // Should return February 15, 2023 (same day in previous month)
+    expect(result).toEqual(new Date(2023, 1, 15));
+  });
+
+  test("handles subscription day that doesn't exist in current month (February edge case)", () => {
+    // Mock the current date to be February 15, 2023
+    vi.setSystemTime(new Date(2023, 1, 15));
+
+    const organization = {
+      billing: {
+        plan: "scale",
+        periodStart: new Date("2022-01-31"), // Original subscription on 31st
+        period: "yearly",
+      },
+    };
+
+    const result = getBillingPeriodStartDate(organization.billing);
+
+    // Should return January 31, 2023 (previous month's subscription day)
+    // since today (Feb 15) is less than the subscription day (31st)
+    expect(result).toEqual(new Date(2023, 0, 31));
+  });
+
+  test("handles subscription day that doesn't exist in previous month (February to March transition)", () => {
+    // Mock the current date to be March 10, 2023
+    vi.setSystemTime(new Date(2023, 2, 10));
+
+    const organization = {
+      billing: {
+        plan: "scale",
+        periodStart: new Date("2022-01-30"), // Original subscription on 30th
+        period: "yearly",
+      },
+    };
+
+    const result = getBillingPeriodStartDate(organization.billing);
+
+    // Should return February 28, 2023 (last day of February)
+    // since February 2023 doesn't have a 30th day
+    expect(result).toEqual(new Date(2023, 1, 28));
+  });
+
+  test("handles subscription day that doesn't exist in previous month (leap year)", () => {
+    // Mock the current date to be March 10, 2024 (leap year)
+    vi.setSystemTime(new Date(2024, 2, 10));
+
+    const organization = {
+      billing: {
+        plan: "scale",
+        periodStart: new Date("2023-01-30"), // Original subscription on 30th
+        period: "yearly",
+      },
+    };
+
+    const result = getBillingPeriodStartDate(organization.billing);
+
+    // Should return February 29, 2024 (last day of February in leap year)
+    expect(result).toEqual(new Date(2024, 1, 29));
+  });
+  test("handles current month with fewer days than subscription day", () => {
+    // Mock the current date to be April 25, 2023 (April has 30 days)
+    vi.setSystemTime(new Date(2023, 3, 25));
+
+    const organization = {
+      billing: {
+        plan: "scale",
+        periodStart: new Date("2022-01-31"), // Original subscription on 31st
+        period: "yearly",
+      },
+    };
+
+    const result = getBillingPeriodStartDate(organization.billing);
+
+    // Should return March 31, 2023 (since today is before April's adjusted subscription day)
+    expect(result).toEqual(new Date(2023, 2, 31));
+  });
+
+  test("throws error when periodStart is not set for non-free plans", () => {
+    const organization = {
+      billing: {
+        plan: "scale",
+        periodStart: null,
+        period: "monthly",
+      },
+    };
+
+    expect(() => {
+      getBillingPeriodStartDate(organization.billing);
+    }).toThrow("billing period start is not set");
+  });
+});

apps/web/lib/utils/billing.ts

@@ -0,0 +1,53 @@
+import { TOrganizationBilling } from "@formbricks/types/organizations";
+
+// Function to calculate billing period start date based on organization plan and billing period
+export const getBillingPeriodStartDate = (billing: TOrganizationBilling): Date => {
+  const now = new Date();
+  if (billing.plan === "free") {
+    // For free plans, use the first day of the current calendar month
+    return new Date(now.getFullYear(), now.getMonth(), 1);
+  } else if (billing.period === "yearly" && billing.periodStart) {
+    // For yearly plans, use the same day of the month as the original subscription date
+    const periodStart = new Date(billing.periodStart);
+    const subscriptionDay = periodStart.getDate();
+
+    // Helper function to get the last day of a specific month
+    const getLastDayOfMonth = (year: number, month: number): number => {
+      // Create a date for the first day of the next month, then subtract one day
+      return new Date(year, month + 1, 0).getDate();
+    };
+
+    // Calculate the adjusted day for the current month
+    const lastDayOfCurrentMonth = getLastDayOfMonth(now.getFullYear(), now.getMonth());
+    const adjustedCurrentMonthDay = Math.min(subscriptionDay, lastDayOfCurrentMonth);
+
+    // Calculate the current month's adjusted subscription date
+    const currentMonthSubscriptionDate = new Date(now.getFullYear(), now.getMonth(), adjustedCurrentMonthDay);
+
+    // If today is before the subscription day in the current month (or its adjusted equivalent),
+    // we should use the previous month's subscription day as our start date
+    if (now.getDate() < adjustedCurrentMonthDay) {
+      // Calculate previous month and year
+      const prevMonth = now.getMonth() === 0 ? 11 : now.getMonth() - 1;
+      const prevYear = now.getMonth() === 0 ? now.getFullYear() - 1 : now.getFullYear();
+
+      // Calculate the adjusted day for the previous month
+      const lastDayOfPreviousMonth = getLastDayOfMonth(prevYear, prevMonth);
+      const adjustedPreviousMonthDay = Math.min(subscriptionDay, lastDayOfPreviousMonth);
+
+      // Return the adjusted previous month date
+      return new Date(prevYear, prevMonth, adjustedPreviousMonthDay);
+    } else {
+      return currentMonthSubscriptionDate;
+    }
+  } else if (billing.period === "monthly" && billing.periodStart) {
+    // For monthly plans with a periodStart, use that date
+    return new Date(billing.periodStart);
+  } else {
+    // For other plans, use the periodStart from billing
+    if (!billing.periodStart) {
+      throw new Error("billing period start is not set");
+    }
+    return new Date(billing.periodStart);
+  }
+};

apps/web/modules/api/v2/management/responses/lib/organization.ts

@@ -1,5 +1,6 @@
 import { cache } from "@/lib/cache";
 import { organizationCache } from "@/lib/organization/cache";
+import { getBillingPeriodStartDate } from "@/lib/utils/billing";
 import { ApiErrorResponseV2 } from "@/modules/api/v2/types/api-error";
 import { Organization } from "@prisma/client";
 import { cache as reactCache } from "react";
@@ -133,22 +134,7 @@ export const getMonthlyOrganizationResponseCount = reactCache(async (organizatio
         }
 
         // Determine the start date based on the plan type
-        let startDate: Date;
-
-        if (billing.data.plan === "free") {
-          // For free plans, use the first day of the current calendar month
-          const now = new Date();
-          startDate = new Date(now.getFullYear(), now.getMonth(), 1);
-        } else {
-          // For other plans, use the periodStart from billing
-          if (!billing.data.periodStart) {
-            return err({
-              type: "internal_server_error",
-              details: [{ field: "organization", issue: "billing period start is not set" }],
-            });
-          }
-          startDate = billing.data.periodStart;
-        }
+        const startDate = getBillingPeriodStartDate(billing.data);
 
         // Get all environment IDs for the organization
         const environmentIdsResult = await getAllEnvironmentsFromOrganizationId(organizationId);

apps/web/vite.config.mts

@@ -74,6 +74,7 @@ export default defineConfig({
         "modules/analysis/**/*.tsx",
         "modules/analysis/**/*.ts",
         "modules/survey/editor/components/end-screen-form.tsx",
+        "lib/utils/billing.ts"
       ],
       exclude: [
         "**/.next/**",